Epidermal growth factor augments postpneumonectomy lung growth

Objective: Epidermal growth factor has been shown to play an important role in prenatal and postnatal lung development, but little is known about its effects on adult lung growth. We hypothesized that postpneumonectomy compen satory lung growth can be augmented by the administration of epidermal grow th factor. Methods: Adult Sprague-Dawley rats were divided into 3 groups. Sham left th oracotomy was performed in the first group (group C), left pneumonectomy in the second group (group P), and left pneumonectomy with administration of epidermal growth factor (0.2 mug/g body weight intraperitoneally, at 72-hou r intervals) in the third group (group E). The right lung growth was studie d in each group 1, 3, 5, 10, and 21 days after the operation. Lung weights tin grams) and volumes tin milliliters) were expressed as a ratio to the to tal body weight tin kilograms) (lung weight and volume indices). Epidermal growth factor receptor was quantitated by using Western blotting. Results: Using analysis of variance and contrast analysis, we noted a signi ficant increase in lung weight index in group E versus group P rats at 3 da ys (3.08 vs 2.75; P = .034) and 21 days (4.62 vs 3.61; P = .006). Lung volu me index was significantly increased in group E versus group P rats at 5 (1 6.98 vs 15.09), 10 (24.48 vs 18.81), and 21 (28.54 vs 21.01) days (P < .001 ). Epidermal growth factor receptor was noted to be up-regulated in the lun gs of animals that received exogenous epidermal growth factor. Conclusions: This study demonstrates that administration of exogenous epide rmal growth factor has a significant effect on postpneumonectomy lung growt h. This process may be mediated by an up-regulation of growth factor recept or expression in the contralateral lung.